Prevalence of fibromyalgia and irritable bowel syndrome and its association with studying medicine, a cross‐sectional study in Al‐Baath University, Syria

Abstract Background The aim of this study is to assess the prevalence rate of fibromyalgia (FM) and irritable bowel syndrome (IBS) among Al‐Baath University students and find out whether studying medicine has an association with a higher prevalence rate. Methods The participants of this observational cross‐sectional study were students aged 18–30 years from Al‐Baath University. A structured self‐estimated electronic questionnaire developed by Google Forms was distributed using social media platforms from 15 February to 15 March, 2023. We used The American College of Rheumatology (ACR) 2016 and Fibromyalgia Rapid Screening Tool criteria to assess the prevalence rate of FM. We used The ROME IV criteria to asses IBS prevalence rate. Results The final sample size was 800 individuals. The prevalence of IBS in the study population was 26.8%. Overall, IBS‐Constipation was the most common subtype, and the prevalence rate was higher among medical students (14%) compared to other colleges (12.8%) (p = .002). The difference in IBS prevalence between males and females was (9.3% vs. 17.5%, p = .283), but this did not reach the statistical significance. The prevalence of FM according to The ACR in the study population was 3.6%. Females had higher prevalence rate than males (3.1% vs. 0.5%, p = .007). The prevalence of FM was also higher in other colleges compared to medicine (2.3% vs. 1.4%, p = .547), but this did not reach statistical significance. Conclusion We found an increased prevalence of IBS among medical students. The prevalence of FM did not show any relation to studying medicine. We recommend additional prospective studies to assess whether studying medicine could be a risk factor for these disorders or not.


INTRODUCTION
The American College of Rheumatology (ACR) identifies fibromyalgia (FM) as suffering severe widespread pain and tenderness in at least 11 or more of 18 specific tender spots for at least 3 months (Wolfe et al., 1990).Several clinical findings, including chronic headaches, paresthesia, sleeping problems, cognitive and mood impairments, psychiatric manifestations (depression, anxiety), and visceral pain, may also be present (Ioachim et al., 2022;Sarzi-Puttini et al., 2020).According to the diagnostic criteria that were applied, the prevalence of FM ranges from 0.2% to 6.6% globally (Cabo-Meseguer et al., 2017;Jones et al., 2015).Females are three times more likely to have FM than males (Cabo-Meseguer et al., 2017).Although there are many factors known to affect the prevalence of FM, the exact pathophysiology of this disease is still relatively unknown.FM prevalence has been linked to childhood difficulties, female sex, smoking, high body mass index (BMI), alcohol abstinence, and preexisting medical disorders in adulthood (Creed, 2020).One factor that has been demonstrated to have a significant effect is stress, and several studies have looked at how different kinds of stress can trigger the development of FM (Lumley et al., 2011).Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder (Lacy & Patel, 2017).Rome foundation identifies IBS as having a recurrent abdominal pain related to defecation in the last 3 months associated with a change in frequency and form of stool (Rome Foundation).IBS was found to be a combination of irritable bowel and irritable brain; the gut is affected by changes in neuroendocrine-immune pathways brought on by stress, which significantly affect the permeability, secretion, motility, and sensitivity of the intestines, and that is what induces an amplification or flareup of IBS symptoms (Qin et al., 2014).Functional syndromes like IBS, FM, and other psychiatric disorders interact in complex ways, and usually coexist, that suggest a common pathogenetic mechanism for FM and IBS (Veale et al., 1991).According to studies, stress levels among medical students are elevated particularly during their undergraduate course (Rosal et al., 1997;Styles, 1993).Excessive workload, difficulties with studying and time management, conflicts in work-life balance, and relationships, medical school peer relations, health concerns, and financial stressors were noted as significant factors in the prevalence of stress among medical students (Hill et al., 2018).So, medical students are more likely to develop chronic pain disorders including FM and IBS.In this research, which is the first of its kind in Syria, the prevalence of IBS and FM will be evaluated among a sample of medical students at one Syrian medical school, and the results will be compared with a group of nonmedical students to find out if studying medicine associates with increasing prevalence of functional disorders.

Study design, setting, duration, participants, and ethical considerations
We conducted an observational cross-sectional study at Al-Baath University, Homs, Syria, from 15 February to 15 March, 2023.The institutional research ethics board approval was obtained from Al-Baath University before performing any study procedure (approval No.54658).The participants were undergraduate students, both medical and nonmedical, at Al-Baath University, ranging in age from 18 to 30 years.The study included all individuals who consented to participate, each responder was given an informed consent form at the first page before filling out the survey.The participants' identities are kept confidential.

Sample size calculation
Assuming an FM prevalence rate of 11.8% as reported in a previous study by Alzabibi et al. (2022), this study required 800 participants to detect a similar prevalence rate with 5% deviation and 95% confidence level.Sample size was calculated using OpenEpi online calculator according to calculation equation mentioned by Charan and Biswas (2013).Sampling method was non-randomized, non-intentional (convenience sampling).

Variables and data collection
A structured self-estimated electronic questionnaire developed by Google Forms was distributed using social media platforms (Facebook, WhatsApp, and Telegram).The questionnaire of the study involved sociodemographic characteristics, including age, gender, and BMI.
Furthermore, participants were asked about smoking, faculty, and curricular year.The ACR 2016 modified screening tool was applied to calculate the prevalence rate of FM, widespread pain index, and symptom severity scale (SSS) are the two parts of the tool (Wolfe et al., 2016).The number of body parts in which the patient reported experiencing pain throughout the previous week is used to calculate the widespread pain index.The SSS evaluates the severity of common FM symptoms such as, fatigue, waking up feeling unrefreshed, cognitive issues, headache, abdominal pain/cramps, and depression over the last 6 months.Moreover, we used Fibromyalgia Rapid Screening Tool (FiRST) criteria to assess the prevalence rate of FM, which included six questions about various FM-related aspects, including widespread pain, fatigue, pain characteristics, non-painful abnormal sensations, functional somatic symptoms, and sleep, and cognitive issues (Perrot et al., 2010).The ROME IV (2016) criteria were used to assess the prevalence of IBS and determine its type (Rome Foundation).This screening tool requires that patients have experienced a recurrent abdominal pain on average at least once per a week during the previous 3 months and that this pain is associated with two or more of the following: abdominal pain related to defecation, a change in frequency of stools, or a change in the shape or appearance of the stool.

Statistical analysis
Statistical analysis was done using SPSS v25 statistics software for Windows.In all cases, a p value <.05 was considered statistically significant.Continuous variables were presented as median and interquartile range; not normally distributed.Categorical variables were presented as percentages and frequencies.Using the Kolmogorov-Smirnov test, numerical factors' normality was checked.
The chi-squared test was used to compare categorical variables, whereas the Mann-Whitney test was used for continuous variables.
Logistic regression model was used to investigate some possible risk factors affecting the development of FM and IBS, and the results were given as 95% confidence interval with odds ratio.We used kappa test to assess the compatibility between ACR and FiRST criteria.

RESULTS
The with no relationship to the academic year (p = .067).Nonsmokers had higher IBS prevalence than the smokers (19.8% vs. 7%, p = .005).The prevalence of IBS was also significantly lower among those with FM according to (ACR) compared to those without FM (1.6% vs. 25.1%,p = .025).The difference in IBS prevalence between males and females was (9.3% vs. 17.5%, p = .283),but this did not reach the statistical significance (Table 2).The logistic regression showed that medical students (p = .002;OR: 1.64, 95%CI: 1.19-2.24)were at a higher risk of having IBS (Table 4).The prevalence of FM according to ACR in the study population was 3.6%.Females had higher FM prevalence than males (3.1% vs. 0.5%, p = .007).The prevalence of FM was also higher in other colleges compared to medicine (2.3% vs. 1.4%, p = .547),but this did not reach statistical significance.However, there was a statistically significant relationship between the medical academic year and FM prevalence (p = .008),where first-year students had the highest prevalence rate, whereas sixth-year students had the lowest one (Table 3).The logistic regression showed that females (p = .012;OR: 3.91, 95%CI: 1.35-11.36)were at a higher risk of having FM (Table 4).
The prevalence of FM according to FiRST in the study population was 14.2%.Cohen's kappa was run to determine the agreement between the two screening tools on diagnosing FM (k = .206,p < .001);kappa coefficient revealed a statistically significant slight agreement.

DISCUSSION
In this study, we aimed to evaluate the prevalence of FM and IBS among Al-Baath University students.To our knowledge, this is the first study of its kind in Syria concerned with the prevalence of these functional disorders in University students.In addition to impairing their psychological and social functioning, FM and IBS have a negative impact on their personal, professional, and everyday lives (Türko glu & Selvi, 2020).In our study, the prevalence of FM in Al-Baath University students was found to be 3.6%.The prevalence of FM between medical students was 1.4%, which is roughly consistent with other studies in different countries, 2% in Turkish medical students (Eyigor et al., 2008) and 9.6% in Saudi medical students (Samman et al., 2021).Our study suggested that there is an association between gender and FM prevalence, where females had higher FM prevalence compared to males with an odds ratio of 3.91 and this result was indicated in previous studies, (Branco et al., 2010;Mäkelä & Heliövaara, 1991).We found no statistically significant association between studying medicine and FM prevalence.Eyigor et al. (2008) Patel et al. (2021) suggested that medical students must be considered a "high-risk" group for FM.Moreover, we found a statistically significant association between medical academic year and FM prevalence, where first-year students had the highest prevalence rate, whereas sixth-year students had the lowest one, maybe due to students' ability to identify and create stress-reduction strategies as they advance in their academic year.Abdulghani et al. (2011) found that the prevalence of stress is higher during the initial 3 years of study.However, Samman et al. ( 2021) suggested that there is no relationship between the academic year and FM prevalence.The prevalence rate of FM according to FiRST was 14.2%, and the level of agreement between the two FM screening tools was slight but significant, the small sample size, small percentage of positive responses, and components of each tool are the main possible factors for this slight agreement.The prevalence  (Costanian et al., 2015).However, medical students in other countries have higher prevalence rate, 31.8% in Jeddah (Ibrahim et al., 2013), 34.2% in Egypt (Abdulmajeed et al., 2011), and28.3% in Pakistan (Naeem et al., 2012).These variations can be caused by genetic, environmental, or a combination of both sources (Kang, 2005).The most common type was constipation and that was consistent with Costanian et al. (2015) study.We found a statistically significant association between studying medicine and IBS prevalence with an odds ratio of 1.64, Chu et al. (2012) reported that medical students have a higher risk of any FBD (functional bowel disorder) than science and engineering students.Wani et al. (2020) suggested that there is an increased prevalence of IBS among medical students.We found no relationship between the academic year and IBS prevalence, Grundmann and Yoon (2010) also found an insignificant difference between preclinical and clerkship students in IBS prevalence.However, Ibrahim et al. (2013) reported that the prevalence of IBS was higher among older students and those from higher academic levels, maybe due to increased clinical load.Our study found that nonsmokers have higher prevalence of IBS than smokers and that was consistent with Mahmood et al. (2020) study.However, Arishi et al. (2021) reported that tobacco smoking is a risk factor for IBS, the exact mechanism which explain the relationship between smoking and bowel disorders is still unclear; it is maybe explained by the alteration of gut microflora composition caused by smoking, as Wang et al. (2012) reported.The prevalence of IBS was higher in females than in males, but this difference was not statistically significant maybe due to small sample size, despite the fact that gender has been linked to an increased risk of developing IBS in previous studies (Arishi et al., 2021;Chu et al., 2012;Ibrahim et al., 2013).
The following limitations may have an impact on how reliable our research is.First, the questionnaire was voluntarily self-administrated suggesting a possibility of information bias.Second, as a cross-sectional research, the current investigation did not take time into account, so we are unable to draw conclusions about causality from these results.
Finally, participants who met the IBS or FM diagnostic criteria were not further evaluated to rule out other potential diseases.However, the current study will surely improve the epidemiological statistics on the prevalence of these functional disorders, IBS and FM, in Syria.

CONCLUSION
We conclude that there is an increased prevalence of IBS among medical students.Although there is a common pathogenetic mechanism for FM and IBS, the prevalence of FM did not show any relation to studying medicine.Our study was a cross-sectional study, so we recommend additional prospective studies to assess whether studying medicine could be a risk factor for these disorders or not.As medical school has a demanding educational system with high academic expectations that could have an impact on future medical practice, we recommend further screening of medical students for disorders like IBS and FM as well as stress reduction due to the possible influence of studying medicine on causing these disorders.
STROBE checklist of observational cross-sectional studies.
Characteristics of the study population.
TA B L E 1 Distribution of irritable bowel syndrome prevalence by respondent characteristics.
reported that the prevalence of generalized soft tissue rheumatism GSTR including FM in medical students was similar to previous reports in the general population.However, TA B L E 2 a Mann-Whitney test.b Chi-squared test.
The logistic regression of the possible risk factors.
TA B L E 4